The best info I can give personally is to not freak out. This info you are getting is very overwhelming, but within a month or so you I can assure you that you will have a Barracks Lawyer Juris Doctorate like most of us sorry souls on here. Reach out to others who have gone thru this process and pay attention to what they tell you in all of the briefs you go to. After a while it will all start to make sense. Good luck!
Patience is key. I noticed a lot of people admitting that they bother their PEBLO or MSC frequently for information, and I personally don't see how that will speed up the process. During this time, you are still getting paid, you have health benefits, so just try your best to continue living the military life until the time comes. If you end up getting out, it will be difficult to plan because of the uncertainty of the process timeline, again, just be patient.
If you don't mind me asking, is your current goal to stay in the military or get out? Advice changes immensely based on that.
My advice is to scan through all the VAs DBQs now. Print any that apply to you. Fill them out at your own pace. Look up anything terms you are unsure of as your read the DBQs. In some cases you need to know the class of medication you are taking to properly answer the DBQs. So fill them out at your own pace so you get it right. A missed check block because you don't understand could mean money lost.
Decide what you want fit or unfit. Double check that that is reality. Then stay focused on moving toward that end.
Use all your resources. Don't be in such a hurry that you leave money on the table. You/your family will need that in the next chapter of life. Get the important things right, but don't sweat the small stuff.